/*
 * @(#)ZipOutputStream.java	1.31 03/12/19
 *
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package com.frame.assist.zip;

import java.io.OutputStream;
import java.io.IOException;
import java.util.Vector;
import java.util.Hashtable;
import java.util.Enumeration;
import java.util.zip.*;
/**
 * This class implements an output stream filter for writing files in the
 * ZIP file format. Includes support for both compressed and uncompressed
 * entries.
 *
 * @author	David Connelly
 * @version	1.31, 12/19/03
 */
public
class ZipOutputStream extends DeflaterOutputStream implements ZipConstants {
	private ZipEntry entry;
	private Vector entries = new Vector();
	private Hashtable names = new Hashtable();
	private CRC32 crc = new CRC32();
	private long written = 0;
	private long locoff = 0;
	private String comment;
	private int method = DEFLATED;
	private boolean finished;

	private boolean closed = false;

	/**
	 * Check to make sure that this stream has not been closed
	 */
	private void ensureOpen() throws IOException {
		if (closed) {
			throw new IOException("Stream closed");
		}
	}
	/**
	 * Compression method for uncompressed (STORED) entries.
	 */
	public static final int STORED = ZipEntry.STORED;

	/**
	 * Compression method for compressed (DEFLATED) entries.
	 */
	public static final int DEFLATED = ZipEntry.DEFLATED;

	/**
	 * Creates a new ZIP output stream.
	 * @param out the actual output stream
	 */
	public ZipOutputStream(OutputStream out) {
		super(out, new Deflater(Deflater.DEFAULT_COMPRESSION, true));
		usesDefaultDeflater = true;
	}

	/**
	 * Sets the ZIP file comment.
	 * @param comment the comment string
	 * @exception IllegalArgumentException if the length of the specified
	 *		  ZIP file comment is greater than 0xFFFF bytes
	 */
	public void setComment(String comment) {
		if (comment != null && comment.length() > 0xffff/3
				&& getUTF8Length(comment) > 0xffff) {
			throw new IllegalArgumentException("ZIP file comment too long.");
		}
		this.comment = comment;
	}

	/**
	 * Sets the default compression method for subsequent entries. This
	 * default will be used whenever the compression method is not specified
	 * for an individual ZIP file entry, and is initially set to DEFLATED.
	 * @param method the default compression method
	 * @exception IllegalArgumentException if the specified compression method
	 *		  is invalid
	 */
	public void setMethod(int method) {
		if (method != DEFLATED && method != STORED) {
			throw new IllegalArgumentException("invalid compression method");
		}
		this.method = method;
	}

	/**
	 * Sets the compression level for subsequent entries which are DEFLATED.
	 * The default setting is DEFAULT_COMPRESSION.
	 * @param level the compression level (0-9)
	 * @exception IllegalArgumentException if the compression level is invalid
	 */
	public void setLevel(int level) {
		def.setLevel(level);
	}

	/**
	 * Begins writing a new ZIP file entry and positions the stream to the
	 * start of the entry data. Closes the current entry if still active.
	 * The default compression method will be used if no compression method
	 * was specified for the entry, and the current time will be used if
	 * the entry has no set modification time.
	 * @param e the ZIP entry to be written
	 * @exception ZipException if a ZIP format error has occurred
	 * @exception IOException if an I/O error has occurred
	 */
	public void putNextEntry(ZipEntry e) throws IOException {
		ensureOpen();
		if (entry != null) {
			closeEntry();	// close previous entry
		}
		if (e.time == -1) {
			e.setTime(System.currentTimeMillis());
		}
		if (e.method == -1) {
			e.method = method;	// use default method
		}
		switch (e.method) {
			case DEFLATED:
				if (e.size == -1 || e.csize == -1 || e.crc == -1) {
					// store size, compressed size, and crc-32 in data descriptor
					// immediately following the compressed entry data
					e.flag = 8;
				} else if (e.size != -1 && e.csize != -1 && e.crc != -1) {
					// store size, compressed size, and crc-32 in LOC header
					e.flag = 0;
				} else {
					throw new ZipException(
							"DEFLATED entry missing size, compressed size, or crc-32");
				}
				e.version = 20;
				break;
			case STORED:
				// compressed size, uncompressed size, and crc-32 must all be
				// set for entries using STORED compression method
				if (e.size == -1) {
					e.size = e.csize;
				} else if (e.csize == -1) {
					e.csize = e.size;
				} else if (e.size != e.csize) {
					throw new ZipException(
							"STORED entry where compressed != uncompressed size");
				}
				if (e.size == -1 || e.crc == -1) {
					throw new ZipException(
							"STORED entry missing size, compressed size, or crc-32");
				}
				e.version = 10;
				e.flag = 0;
				break;
			default:
				throw new ZipException("unsupported compression method");
		}
		e.offset = written;
		if (names.put(e.name, e) != null) {
			throw new ZipException("duplicate entry: " + e.name);
		}
		writeLOC(e);
		entries.addElement(e);
		entry = e;
	}

	/**
	 * Closes the current ZIP entry and positions the stream for writing
	 * the next entry.
	 * @exception ZipException if a ZIP format error has occurred
	 * @exception IOException if an I/O error has occurred
	 */
	public void closeEntry() throws IOException {
		ensureOpen();
		ZipEntry e = entry;
		if (e != null) {
			switch (e.method) {
				case DEFLATED:
					def.finish();
					while (!def.finished()) {
						deflate();
					}
					if ((e.flag & 8) == 0) {
						// verify size, compressed size, and crc-32 settings
						if (e.size != def.getBytesRead()) {
							throw new ZipException(
									"invalid entry size (expected " + e.size +
											" but got " + def.getBytesRead() + " bytes)");
						}
						if (e.csize != def.getBytesWritten()) {
							throw new ZipException(
									"invalid entry compressed size (expected " +
											e.csize + " but got " + def.getBytesWritten() + " bytes)");
						}
						if (e.crc != crc.getValue()) {
							throw new ZipException(
									"invalid entry CRC-32 (expected 0x" +
											Long.toHexString(e.crc) + " but got 0x" +
											Long.toHexString(crc.getValue()) + ")");
						}
					} else {
						e.size  = def.getBytesRead();
						e.csize = def.getBytesWritten();
						e.crc = crc.getValue();
						writeEXT(e);
					}
					def.reset();
					written += e.csize;
					break;
				case STORED:
					// we already know that both e.size and e.csize are the same
					if (e.size != written - locoff) {
						throw new ZipException(
								"invalid entry size (expected " + e.size +
										" but got " + (written - locoff) + " bytes)");
					}
					if (e.crc != crc.getValue()) {
						throw new ZipException(
								"invalid entry crc-32 (expected 0x" +
										Long.toHexString(e.crc) + " but got 0x" +
										Long.toHexString(crc.getValue()) + ")");
					}
					break;
				default:
					throw new InternalError("invalid compression method");
			}
			crc.reset();
			entry = null;
		}
	}

	/**
	 * Writes an array of bytes to the current ZIP entry data. This method
	 * will block until all the bytes are written.
	 * @param b the data to be written
	 * @param off the start offset in the data
	 * @param len the number of bytes that are written
	 * @exception ZipException if a ZIP file error has occurred
	 * @exception IOException if an I/O error has occurred
	 */
	public synchronized void write(byte[] b, int off, int len)
			throws IOException
	{
		ensureOpen();
		if (off < 0 || len < 0 || off > b.length - len) {
			throw new IndexOutOfBoundsException();
		} else if (len == 0) {
			return;
		}

		if (entry == null) {
			throw new ZipException("no current ZIP entry");
		}
		switch (entry.method) {
			case DEFLATED:
				super.write(b, off, len);
				break;
			case STORED:
				written += len;
				if (written - locoff > entry.size) {
					throw new ZipException(
							"attempt to write past end of STORED entry");
				}
				out.write(b, off, len);
				break;
			default:
				throw new InternalError("invalid compression method");
		}
		crc.update(b, off, len);
	}

	/**
	 * Finishes writing the contents of the ZIP output stream without closing
	 * the underlying stream. Use this method when applying multiple filters
	 * in succession to the same output stream.
	 * @exception ZipException if a ZIP file error has occurred
	 * @exception IOException if an I/O exception has occurred
	 */
	public void finish() throws IOException {
		ensureOpen();
		if (finished) {
			return;
		}
		if (entry != null) {
			closeEntry();
		}
		if (entries.size() < 1) {
			throw new ZipException("ZIP file must have at least one entry");
		}
		// write central directory
		long off = written;
		Enumeration e = entries.elements();
		while (e.hasMoreElements()) {
			writeCEN((ZipEntry)e.nextElement());
		}
		writeEND(off, written - off);
		finished = true;
	}

	/**
	 * Closes the ZIP output stream as well as the stream being filtered.
	 * @exception ZipException if a ZIP file error has occurred
	 * @exception IOException if an I/O error has occurred
	 */
	public void close() throws IOException {
		if (!closed) {
			super.close();
			closed = true;
		}
	}

	/*
     * Writes local file (LOC) header for specified entry.
     */
	private void writeLOC(ZipEntry e) throws IOException {
		writeInt(LOCSIG);	    // LOC header signature
		writeShort(e.version);      // version needed to extract
		writeShort(e.flag);         // general purpose bit flag
		writeShort(e.method);       // compression method
		writeInt(e.time);           // last modification time
		if ((e.flag & 8) == 8) {
			// store size, uncompressed size, and crc-32 in data descriptor
			// immediately following compressed entry data
			writeInt(0);
			writeInt(0);
			writeInt(0);
		} else {
			writeInt(e.crc);        // crc-32
			writeInt(e.csize);      // compressed size
			writeInt(e.size);       // uncompressed size
		}
		byte[] nameBytes = getUTF8Bytes(e.name);
		writeShort(nameBytes.length);
		writeShort(e.extra != null ? e.extra.length : 0);
		writeBytes(nameBytes, 0, nameBytes.length);
		if (e.extra != null) {
			writeBytes(e.extra, 0, e.extra.length);
		}
		locoff = written;
	}

	/*
     * Writes extra data descriptor (EXT) for specified entry.
     */
	private void writeEXT(ZipEntry e) throws IOException {
		writeInt(EXTSIG);	    // EXT header signature
		writeInt(e.crc);	    // crc-32
		writeInt(e.csize);	    // compressed size
		writeInt(e.size);	    // uncompressed size
	}

	/*
     * Write central directory (CEN) header for specified entry.
     * REMIND: add support for file attributes
     */
	private void writeCEN(ZipEntry e) throws IOException {
		writeInt(CENSIG);	    // CEN header signature
		writeShort(e.version);	    // version made by
		writeShort(e.version);	    // version needed to extract
		writeShort(e.flag);	    // general purpose bit flag
		writeShort(e.method);	    // compression method
		writeInt(e.time);	    // last modification time
		writeInt(e.crc);	    // crc-32
		writeInt(e.csize);	    // compressed size
		writeInt(e.size);	    // uncompressed size
		byte[] nameBytes = getUTF8Bytes(e.name);
		writeShort(nameBytes.length);
		writeShort(e.extra != null ? e.extra.length : 0);
		byte[] commentBytes;
		if (e.comment != null) {
			commentBytes = getUTF8Bytes(e.comment);
			writeShort(commentBytes.length);
		} else {
			commentBytes = null;
			writeShort(0);
		}
		writeShort(0);		    // starting disk number
		writeShort(0);		    // internal file attributes (unused)
		writeInt(0);		    // external file attributes (unused)
		writeInt(e.offset);	    // relative offset of local header
		writeBytes(nameBytes, 0, nameBytes.length);
		if (e.extra != null) {
			writeBytes(e.extra, 0, e.extra.length);
		}
		if (commentBytes != null) {
			writeBytes(commentBytes, 0, commentBytes.length);
		}
	}

	/*
     * Writes end of central directory (END) header.
     */
	private void writeEND(long off, long len) throws IOException {
		writeInt(ENDSIG);	    // END record signature
		writeShort(0);		    // number of this disk
		writeShort(0);		    // central directory start disk
		writeShort(entries.size()); // number of directory entries on disk
		writeShort(entries.size()); // total number of directory entries
		writeInt(len);		    // length of central directory
		writeInt(off);		    // offset of central directory
		if (comment != null) {	    // zip file comment
			byte[] b = getUTF8Bytes(comment);
			writeShort(b.length);
			writeBytes(b, 0, b.length);
		} else {
			writeShort(0);
		}
	}

	/*
     * Writes a 16-bit short to the output stream in little-endian byte order.
     */
	private void writeShort(int v) throws IOException {
		OutputStream out = this.out;
		out.write((v >>> 0) & 0xff);
		out.write((v >>> 8) & 0xff);
		written += 2;
	}

	/*
     * Writes a 32-bit int to the output stream in little-endian byte order.
     */
	private void writeInt(long v) throws IOException {
		OutputStream out = this.out;
		out.write((int)((v >>>  0) & 0xff));
		out.write((int)((v >>>  8) & 0xff));
		out.write((int)((v >>> 16) & 0xff));
		out.write((int)((v >>> 24) & 0xff));
		written += 4;
	}

	/*
     * Writes an array of bytes to the output stream.
     */
	private void writeBytes(byte[] b, int off, int len) throws IOException {
		super.out.write(b, off, len);
		written += len;
	}

	/*
     * Returns the length of String's UTF8 encoding.
     */
	static int getUTF8Length(String s) {
		int count = 0;
		for (int i = 0; i < s.length(); i++) {
			char ch = s.charAt(i);
			if (ch <= 0x7f) {
				count++;
			} else if (ch <= 0x7ff) {
				count += 2;
			} else {
				count += 3;
			}
		}
		return count;
	}

	/*
     * Returns an array of bytes representing the UTF8 encoding
     * of the specified String.
     */
	private static byte[] getUTF8Bytes(String s) {
		return s.getBytes();
//	char[] c = s.toCharArray();
//	int len = c.length;
//	// Count the number of encoded bytes...
//	int count = 0;
//	for (int i = 0; i < len; i++) {
//	    int ch = c[i];
//	    if (ch <= 0x7f) {
//		count++;
//	    } else if (ch <= 0x7ff) {
//		count += 2;
//	    } else {
//		count += 3;
//	    }
//	}
//	// Now return the encoded bytes...
//	byte[] b = new byte[count];
//	int off = 0;
//	for (int i = 0; i < len; i++) {
//	    int ch = c[i];
//	    if (ch <= 0x7f) {
//		b[off++] = (byte)ch;
//	    } else if (ch <= 0x7ff) {
//		b[off++] = (byte)((ch >> 6) | 0xc0);
//		b[off++] = (byte)((ch & 0x3f) | 0x80);
//	    } else {
//		b[off++] = (byte)((ch >> 12) | 0xe0);
//		b[off++] = (byte)(((ch >> 6) & 0x3f) | 0x80);
//		b[off++] = (byte)((ch & 0x3f) | 0x80);
//	    }
//	}
//	return b;
	}
}
